add workflow

.circleci/config.yml

@@ -11,13 +11,22 @@ jobs:
           docker push ajaytripathy/kubecost-cost-model:$TAG
   deploy:
     machine: true
-    filters:
-      branches:
-        only:
-          - master
     steps:
       - checkout
       - run: |
           docker login -u $DOCKER_USER -p $DOCKER_PASS
           docker build -t ajaytripathy/kubecost-cost-model:latest .
           docker push ajaytripathy/kubecost-cost-model:latest
+
+workflows:
+  version: 2
+  build-and-deploy:
+    jobs:
+      - build
+      - deploy:
+          requires: 
+            - build
+          filters:
+            branches:
+              only:
+                - master